Needle bar and presser foot control device for automatic sewing and embroidering machines



Nov. 12, 1968 H. RoLAUr-'Fs 3,410,238

NEEDLE BAR AND PRESSER FOOT CONTROL DEVICE FOR AUTOMATIC SEWING ANDEMBROIDERING MACHINES Filed Oct. 24, 1965 6 Sheets-Sheet l lNvENTOR f/as64u/ 5 BY l 7 H. ROLAUFFS NEEDLE BAR AND PRESSER FOOT CONTROL DEVICE FORAUTOMATIC SEWING AND EMBROIDERING MACHINES 6 Sheets-Sheet 2 Filed Oct.24, 1965 INVENTOR. Ha/s E70/QW; BY

3,410,238 TOMATIC Nov. 12, 1968 H. RoLAUFFs ESSER FOOT CONTROL DEVICEFOR AU SEWING AND EMBROIDERING MACHINES NEEDLE BAR AND PR 6 Sheets-Sheet5 Filed Oct. 24, 1965 INVENTOR. 6W-r y/QWJ BY Nov. 12, 1968 H. ROLAUFFS3,410,238

NEEDLE EAR AND PREssER FOOT CONTROL DEVICE FOR ,AUTOMATIC sEwING ANDEMBROIDERING MACHINES Filed Oct. 24, 1965 6 Sheets-Sheet 4 Nov. 12, 1968H. RoLAuFr-s 3,410,238

NEEDLE BAR AND PRESSER FOOT CONTROL DEVICE FOR AUTOMATIC SEWING ANDEMBROIDERING MACHINES Filed Oct. 24, 1965 6 Sheets-Sheet 5 INVENTOR Nov.12, 1968 H. RoLAUFr-s 3,410,238.

NEEDLE BAR AND PRESSER FOOT CONTROL DEVICE FOR AUTOMATIC SEWING ANDEMBROIDERING MACHINES 6 Sheets-Sheet 6.

Filed Oct. 24, 1965 Fig. 7

INVENTOR.

United States Patent O 3,410,238 NEEDLE BAR AND PRESSER FUOT CUNTROLDEVICE FOR AUTOMATIC SEWING AND EMBROIDERING MACHINES Hans Rolauls,Krefeld, Germany, assigner to Maschinenfabrik Carl ZangsAktiengeseilschaft, Krefeld, Germany Filed Oct. 24, 1965, Ser. No.504,362 Claims priority, application Germany, June 25, 1965, M 65,711 9Claims. (Cl. 112-221) ABSTRACT OF THE DISCLOSURE Multiple needle machinehaving a presser foot for each individual needle with a drivingmechanism common to all of the needles and operating continuously. Eachneedle has control means by which it can be made selectively operativeor be held in retracted position. Each presser foot is lifted by thedriving mechanism each time the respective needle retracts and is heldin retracted position by the respective needle bar when the needle isheld in retracted ineffective position.

The present invention relates to a needle bar and presser foot controldevice for automatic sewing and embroidering -machines which during therunning of the machines are adapted to take the needles and presser footeither individually or in groups out of operation and later to returnthe same to operation.

Arrangements of this type are known which, however, do not meet allmodern requirements and have a number of drawbacks.

Thus, while a heretofore known arrangement of the type involvedfurnishes a solution to the needle bar control, it does not solve theproblem of stopping the presser foot. Furthermore, the realization ofthe control device requires so much space that this design cannot beemployed where, for instance in vmulti-needle automats, the distancebetween the individual drive is narrow.

A further heretofore known design represents a solution for the needlebar control which While requiring a little space only is not able tocarry out the turning on and turning off during the relatively highspeed of the machine. Moreover, this design lacks the presser footcontrol.

Another heretofore known control arrangement has no positive couplingbetween needle bar and driving means therefor but only a frictionalcoupling. Such a design causes difficulties in sewing and embroideringoperations because -it is no advantage when during hard stitches theneedle movement disengages itself. Also these hard stitches which occurfrom time to time have to be carried out in practice and must not beomitted. Modern needles are able to withstand such stresses. This designfurthermore fails to present a solution for the pressure foot control.

It is, therefore, an object of the present invention t provide a needlebar and presser foot control arrangement which will overcome the above-mentioned drawbacks.

It is another object of this invention to provide a needle bar andpresser foot control for automatic sewing and embroidering machineswhich will be able in a simple manner individually or in groups to turnand turn off the operation of needle bars and presser foot.

These and other objects and advantages of the invention will appear moreclearly from the following specification in connection with theaccompanying drawings, in which:

3,410,238 Patented Nov. 12, 1968 FIG. 1 shows a front view of amulti-needle embroidering machine in connection with which the presentinvention may be employed.

FIG. 2 is a top view of FIG. 1.

FIG. 3 illustrates a front view and partial section of an individualembroidering unit -of a multi-needle embroidering machine `within therange X of FIG. 1.

FIG. 4 is a section along the line A-B of FIG. 3.

FIG. 5 shows the front view of an individual embroidering unit accordingto FIG. 3, however, with the end face cover mounted thereon.

FIG. 6 is a front view of the outermost right-hand embroidering unitwith actuating magnet.

FIG. 7 is an electric control diagram for controlling the fast couplingaccording to the invention.

In realizing the objects outlined above, the present invention suggestswhen stopping the operation of the needle bars simultaneously to stopthe movement of the respective presser feet pertaining thereto, byplacing arms on the needle holders, whereas when restoring operation ofthe needle bars, at the same time the presser feet are also restored tooperation. The coupling sleeves connected to the needle bars, and thecoupling pawls under the load of torsion springs are positively coupledto each other. For purposes of automatically controlling all needle barsand presser feet, there is provided a two-position actuating magnet themagnet coils of which are, in conformity with the commands issued by acontrol card, alternately connected to a source of current by menas of astep by step control mechanism. Instead of a twoposition actuatingmagnet, also a correspondingly controlled compressed air or pressure oilcylinder may be employed. Advantageously, the turning on and offmechanism, for instance the manual coupling of the needle bars andpresser feet may through a switch be connected with an electric controldevice of the upper threads so that the automat will be stopped `when athread breaks.

An arrangement of this type also funrishes the possibility of displacingthe sewing or embroidery material from one seam to the other or from oneembroidery design to another without leaving stepping stitches. Suchstepping stitches are disadvantageous inasmuch as they later have to becarefully taken out, aside from the fact that the needle hole will withcertain type of fabric remain visible after the stepping stitches havebeen removed.

The individual control of certain needles is required, for instance,also with multi-needle embroidering automats when the pattern has to bechanged. The simultaneous stopping of the presser foot together with aneedle as has 'been made possible by the present invention is requiredin particular when working on sensitive-goods, in order to avoidpressure areas on the goods.

The invention will now `be described in detail in connection with amulti-needle machine, for instance a multineedle portal embroideringmachine. More specifically referring to the drawings, FIGS. 1 and 2 showthe machine frame 1 with a portal 2 for receiving the embroideringtools, the carrier 3 for receiving a looper 4 with the lower threadbobbin, the embroidering frame 5 for mounting the goods 6 to beembroidered, the beam 7 for winding up the goods, the deviating roller7a, the control automat 8 for the movement 0f the embroidering frame 5through the driving link system 9 and for initiating the controlfunctions in conformity with the program of control card 10. FIGS. l and2 also show the stand 11 for the yarn roll for the upper yarn bobbins12, the thread guide 13 for the upper thread, and the table plate 14.Drive motor 15 drives the control automat 8 through the driving frame16, and furthermore drives the embroidering tools in portal 2 and thelfooper 5 in carrier 3. FIGS.

1 to 4 also indicate the angle steel strip 17 for connecting the controlelements and the two-position actuating magnet 18.

With an embroidering unit according to FIGS. 3 to 6, needle 19a is bymeans of a needle holder 19b clamped in needle bar 19. Screwed to needlebar 19 is a coupling sleeve 20 `which in its uppermost position ofmovement engages a ring 21 of synthetic material which latter thenengages the upper needle bar guiding bushing 22. Needle bar 19 issecured against turning by means of a slot 19C and a trunnion screw 23.Also screwed to said bushing 22 is a holder 24 for the lock catch 25which is adapted to rotate about pivots 26a and 26h. A control 'bar 27which is journalled at the upper and lower end in the portal is arrangedadjacent the needle bar 19. When control bar 27 occupies its uppercontrol position, the spring-loaded 'ball 28 (FIG. 4) engages notch 27a,whereas when control bar 27 occupies its lower position, `ball 28engages notch 28b (FIG. 3). The spring (not illustrated) which acts uponball 28 is preloaded and held by screw 29 (FIG. 6). Control pin 27e(FIG. 3) which is screwed into control bar 27 and secured by a counternut serves for controlling lock catch 25. Control =bar 27 is providedwith recesses 27d for controlling coupling 40 (FIGS. 3 and 4). Thepresser foot 31 which presses on the material and is under the load of apressure spring 30 is guided upon the lower part of control bar 27.Presser foot 31 is -by means of a slot 2a and portal 2 and by bearing 32secured against turning (FIG. 3). An arm 31a of presser foot 31 isadapted through needle bar 19 and needle holder 19b to turn the movementof the presser foot on and oit.

Rotatabie crank pin 33 which is drivingly connected to motor is adaptedthrough the intervention of a connecting rod 34 to oscillate drivinglever 35 of an embroidering unit (FIG. 4). Through the intervention offollower screw 36, shaft 37 journalled in a plurality of `bearings 38(FIG. 3) is oscillated and thus all other driving levers 35 whichpertain to individual embroidering units and are connected to shaft 37will oscillate together with the latter. The oscillating driving lever35a will through connecting rod 39 (FIG. 3) cause clutch 40 to move backand forth. Clutch 40 will in disengaged condition slide up and down onneedle bar 19. This clutch is primarily composed of pivot bolts 40a and4012, torsion springs 40e and 40d, clutch pawls 40C and 40f, rollerbolts 40g and 40h, control rollers 401' and 40k, and rollers 401 and40m.

Each embroidering unit has associated therewith atakeup lever 41. All ofthe take-up levers 41 are connected to an oscillating shaft 42 commonthereto. Shaft 42 is journalled in a plurality of rings 43 and obtainsits oscillating movement from a cam or crank drive (not illustrated). Atthe head of the control bar 27 there is arranged a manual clutch 44which comprises a clutch bolt 44a, a pressure spring 44b, a clutch knob44e and a lever 44d (FIG. 4). This manual clutch 44 is by means of screw44e xedly connected to control "bar 27 (FIG. 3). For purposes ofcontrolling all 'or some selected control bars 27 from a centralstation, there are provided control levers 45. Each control lever 45 isrotatably journalled on a bolt 44a which is connected to an angle steelstrip 17. The means for effecting the said central control alsocomprises the clamping members 45b, control bar 46, angle lever 47, bolt47a likewise connected to strip 17, clamping member 47b, fork-shapedhead 18a with pivot bolts 18b, and the twoposition actuating magnet 18.It is a matter of course that the two-position actuating magnet 18 mayalso ybe replaced by other stroke producers, as for instance compressedair or pressure oil cylinder piston means. Furthermore, the importantpart of the two-position actuating magnet 18 comprises, in conformitywith FIG. 6, the armature 18e, the bar 18d, the front magnet coil 18e,the rear magnet coil 181, the abutments 18g and 18h and the three-wireconductors 181, 18k and 181.

In each embroidering unit, the upper thread ,12a passes from the upperyarn bobbin 12 through thread guide 13 a pretensioning device 48, wireadjustable main clamping means 49, to the thread pulling device 50 (FIG.5). The thread pulling spring 50a which is moved by the upper thread 12ain conformity with the rhythm of the movement of the take-up lever 41 iselectrically connected to the end cover 51 and thus to the mass of theportal 2 and of the machine frame 1. On the other hand, however, theabutment pin 5012 is insulated and connected with an electric conductor52. From the thread pulling device 50, the upper thread 12a passesthrough the eye of the take-up lever 41 and from there through thedeviating member 53, through the eye of needle 19a and tothe line ofmaterial 54. Conductor 52 leads to a contact 55a of a switch 55 which inresponse to the actuation of its control yoke 55c is adapted through theintervention of the manual clutch 44 and push rod 55d to separate thecontacts 55a and 55h electrically. From contact 55b a conductor 56 leadsto a plug 57 which engages a common conducting strip 58 which iselectrically insulated from and mounted on the angle strip 17.

The control diagram shown in FIG. 7 illustrates by way of example oneway in which the electric control for the clutch may be effected. Inaddition to the above mentioned parts, the diagram illustrates furtherelectric devices and, more specically, a transformer 59 for opening alow control voltage, a rectifier 60 for producing the direct currentvoltage which is required for exciting the two-position actuating magnet18, and the step by step control mechanism 61 which with each currentimpulse arriving at coil 61b alternately Connects its contact 61a withthe terminals 61C and 61d. Metal foils 10a and 10b glued to the marginalportion of control card 10 shortcircuit contacts 62a and 6217 for thetime period during which the card slides by. Furthermore, there isprovided a control relay 63 for disconnecting the drive for themulti-needle machine. The interrupter contact 65 is controlled by a camdisc 66. Contact 65 controls the scanning point for the upper thread 12aby means of pressure spring 50a. More specifically, the interruptercontact 65 is closed at the very moment when the upper thread 12a istaut. Cam disc 66 is connected to machine main shaft 67. Dash line 68represents the electrically conductive mass connection. Lines 69 to 74illustrate connecting conductors.

OPERATION A.-1Manual control of individual needle bars and their presserfeet In starting position, the clutch pawls 40e and 40 are positivelyconnected to the clutch sleeve 20. The control bar 27 occupies its upperrest position while the armature 18e and the bar 18d have by thetwo-position magnet 18 been brought into the pushed-out position, andthe Inachine is running.

Clutch knob 44e is pulled out and turned by 90 and member 44d is movedto engage groove 44j. Clutch 44 is moved downwardly until the controlbars 27 engage notch means 27b. The upper end of the recess 27d on bothsides is now located lower by the distance of notch means 27b and 27a.Furthermore, control pin 27e` with control bar 27 has moved downwardlyand thus permits the locking catch 25 due to its own weight or the forceof a torsion spring to turn somewhat in clockwise direction about pivots26a and 261'). Needle bar 19 moves upwardly and downwardly while beingdriven by the driving lever 35a, connecting bar 39 and clutch 40. Duringthe upward movement of needle bar 19 which follows the downward controlof control bar 27, the following operations will take place.

Control rollers 401 and 40k will spread at the end 0f the recess 27d ofcontrol bar 27 and will thus open the clutch between the clutch pawls40e and 40]c and clutch sleeve 20, However, rollers 401 and 40m remainon the arched surfaces 2Gb and 20c (FIGS. 3 and 4) and press the clutchsleeve and thus the needle bar 19 up into the upper dead center point.Nose 20a of clutch sleeve 20 will during this upward movement slide pastnose a of locking catch 25 by pressing the pre-loaded locking catch 25somewhat in counter-clockwise direction, said locking catch beingpre-loaded by its own weight or a tension spring. As soon as nose 20ahas moved past nose 25a, nose 25a places itself below nose 20a and thusholds clutch sleeve 20 and consequently needle bar 19 connected theretoin the position of its upper movement reversal.

Rollers 40! and 40m of the spread clutch pawls 40e and 401 roll back andforth on needle bar 19 and hold clutch pawls 40e and 40j spread alsowhen the control rollers 401' and 40k during their upward movement againcome into the range of recess 27d. At said point of `the upper movementreversal of clutch 40, rollers 40! and 40m are prevented from engagingthe rest positions 19d of needle bar 19 by control rollers 401' and 40kwhich in this position take care for the spreading of the clutch pawls40e and 40f. During the embroidering operation, presser foot 31 is atpoint 31b by means of abutment 40n lifted off the line 45 of thematerial when the needle bar 19 moves upwardly. Abutment 40u is providedwith a shock absorbing liner 40o. When the movement of needle bar 19 isinterrupted and needle bar 19 is arrested in its upper position ofmovement reversal, presser foot 31 is arrested by its arm 31a restingupon needle holder 19b against the thrust of pressure spring 30.

Clutch knob 44e is pulled out and turned by 90 and ward shift of manualclutch 44 be actuated so that contacts 55a and 55h open and thereby turnolf the electric upper thread control for the stopped embroidering unit.

FIGS. 5 and 7 will illustrate the function of the electric upper threadcontrol. Upper thread 12a passes through the yoke of the thread pullingtorsion spring 50a and leads the same from the abutment pin 50b when thetakeup lever 41 pulls the thread taut during the upward movement. Duringthis time period in which the upper thread 12a is normally taut, camdisc 66 closes the interrupter contact 65 so that the current may passfrom terminals 59a of transformer 59 through conductor 71, the coil ofcontrol relay 63, conductor 70, interrupter contact 65, conductor 69,plug strip 58, and conductor 56 to `contact 55h. When the needle bar 19is in operation, the current furthermore passes through contact 55a andconductor 52 to abutment pin 50h. Thread pulling tension spring 50a iselectrically connected through mass connecting line 68 with the terminal59b of transformer 59.. When the upper thread 12a is missing because itis too loose or it is torn, the thread pulling tension spring 50a andabutment pin S0b remain electrically connected so that for the durationduring which the interrupter contact 56 is switched on, the coil ofcontrol relay 63 will due to cam disc 66 receive current. By means ofthe contact of control relay 63, the turning off of the machine may thenbe initiated in the well known manner.

In view of the breakingvof the two contacts 55a and 55b, the electriccontrol of the respective upper thread 12a is put out of operation. Thereturn to operation of individual needle bars 19 and presser foot 31 iseffected by additionally turning on the respective control bars 27 untilthey engage notch means 27a. As a result thereof, the locking catch 25is by means of control pin 27e` turned in counter-clockwise direction sothat nose 25a will relieve nose 20a of clutch sleeve 20. The recesses27d on both sides which are provided in control bar 27 have again freed`control rolls 401' and 40k so that rollers 40! and 40m can snap intothe rest position 19d when clutch 40 has reached the position of theupper movement reversal. In view of this engagement, also the positiveengagement between the clutch members 40e and 40f and clutch sleeve 20is restored so that the respective needle bar 19 is again moved upwardlyand downwardly. The above described return to operation is effectedinanually in a shock-free manner because the clutch engagement iseffected at the upper dead center point of the upward and downwardmovement of clutch 40. During this re-engagement, contacts 55a and SSbagain close so that the respective upper threads 12a are againelectrically controlled or checked.

B.-Automatic control of all needle bars and presser feet At the startingposition, all manual clutches 44 are connected through clutch ibolts 44awith control levers 45. All needle bars 19 ane engaged and in operation,armature 18e and bar 18d of the two-position actuating magnet 18 are inpushed-out position, and the machine is running. When the metal foil 10aglued to control card 10 (FIG. 7) passes by, the contacts 62a and 62bare short-circuited. As a result thereof, coil 61b of step by stepcontrol mechanism 61 will for the duration of the establishment ofcontact receive current from the transformer 59 through terminal 59b,line 73, contact 62a, metal foil 10a, contact 62b, line 74, coil 61b,line 71a, and terminal 59a. This `short period current impulse switchescontact 61a from connection with terminal 61C to connection withterminal 61d. Prior to the thus described switch-over operation,magnetic coil 18e was located in the following circuit: rectifier I60,line 18k, magnetic coil 18e, line 181, terminal 61C, contact 61a, line72, rectifier 60. As a result thereof, armature 18e and thus bar 18dwere pulled into magnetic coil 18e which means were pushed out,

After this reversal, magnetic coil 181 is, due to the exchange ofconductors 181 and 18 in the direct current circuit so located thatarmature 18C and thus bar 18d are pulled in. In view of the pulling inof bar 18d, angle lever 47 is turned in clockwise direction about bolt47a whereby control bar 46 is lmoved in leftward direction. As a resultthereof, all of the control levers 45 tilt in clockwise `direction andIby means of the manual clutches 44 move all of the control bars 27downwardly.

The subsequent disengagement of all needle bars 19 and presser feet 31is effected in precisely the Imanner which has been described inconnection with the manual control of individual needle bars 19 andpresser feet 31.

The return of all embroidering units to operation is initiated by thenext metallic foil 10b. In view of a shortcircuiting of contacts 62a and62b, the step by step control mechanism 61 again switches its contact61a into engagement with contact 61e whereby magnetic coil 18e isexcited and `pushes out armature 18C together with bar 18d. Through theintervention of angle lever 47 and control lever 45, all control barsare pulled upwardly whereby in a manner `described above, all needlebars 19 and presser feet 31 are again returned to operation.

The Idescribed electric control by metal foils 10a and 10b may, ofcourse, also 'be replaced by other constructions as, for instance, lightbarriers which are controlled by the perforations in the card, or byreflex light barriers reacting upon rellex foils glued to card 10. Ifdesired, also two electric contact members normally separated from eachother by the control card may be permitted to Contact each other througha card perforation at the control points.

C Automatic control of needle bars and presser feet groups For purposesof group contro-l, it is required that the embroidering units which areto remain continuously in operation or out of operation be adjustedaccordingly by disengaging the manual clutches 44 from the controllevers 45 and engaging the respective notches 27a or 27b. All unitswhich remain enga-ged with the control levers 45 through rmanualclutches 44 will follow the control impulses of control card 10.

It is, of course, to be understood that the present invention is, by nomeans, limited to the particular arrangement set forth above but alsocomprises any modifications within the scope of the appended claims.

What is claimed is:

1. In an arrangement for embroidering and sewing; a plurality ofreciprocable needle bars, a reciprocable presser foot for each needlebar, drive means for driving said needle bar, clutch means `for eachneedle bar operable for clutching the respective need-le bar to saiddrive means, a locking pawl for each needle bar for locking therespective needle bar in retracted position `during continued operationof said driving means, a control rod for each needle Ibar displaceablefrom a first position wherein the said locking pawl for the respectiveneedle bar is ineffective and the said clutch means for the respectiveneedle bar is effected into a second position wherein the said lockingpawl is eifective and the said clutch means is ineffective, abutmentmeans including cooperating elements lon `said drive means and saidpresser foot for retractiug said presser foot during retracting movementof said needle bar, and other abutment means including cooperatingelements on said needle bar and said presser foot interengageatble inthe retracted position of said needle bar for holding ysaid presser footin retracted position during continued operation of said drive means.

2. The arrangement according to claim 1 which includes means forImanually displacing each said control rod from either of its saidposition to the other, and power operable means for power displacementof the control rods .from either of their said positions to the other,and means for selectively connecting each of said control rods to saidpower operable means.

3. The arrangement according to claim 1 in which said power operablemeans includes a two position actuator.

4. The arrangement according to claim 3 in which said actuator comprisesa pair of solenoids and an armature moveable thereby.

5. The arrangement according to claim 4 in which switch means isprovided for completing an energizing circuit to said solenoidsalternately, and a control card, and means in circuit with said switchand said solenoids and scanning said control card for completing saidenergizing circuits according to the region of the card being scanned.

6. The `arrangement according to claim 1 in which said clutch meansincludes a clutch sleeve tiXed to each needle car, a drive elementconnected to said driving means, and drive pawl means on each driveelement for the respective sleeve and spring urged toward drivingengagement with the respective sleeve and moveable out of drivingengagement with the respective sleeve by the respective control rod whenthe latter is moved into its said second position.

7. The arrangement according to claim 6 in which each said sleeve hasrib means projecting laterally therefrom on opposite sides in the pathof movement of said pawls, and said pawl means comprising a notched pawlmember pivotally mounted on said drive element on each side of saidsleeve, said notches engaging said rib means when said control rod ismoved into its said iirst position.

S. The arrangement according to claim 1 in which said clutch meansincludes a clutch sleeve on each needle bar, and drive pawl means foreach sleeve arranged on respectively opposite sides thereof andconnected to said driving means and spring urged toward drivingengagement with the respective sleeve, said control rod for each needlebar including means operable when the control rod is moved into its saidsecond position and the pertaining needle bar approaches its retractedposition for engaging said pawls and moving said pawls apart to effectdisengagement of said pawls from the respective said sleeve.

9. In an arrangement for embroidering and sewing; a plurality ofreciprocable needle bars, a reciprocable presser foot for each needlebar, drive means for driving said needle bars, clutch means forclutching each needle bar to said drive means, a locking pawl forlocking each needle bar in retracted position, a control rod for eachneedle bar displaceable from a first position wherein said locking pawlis ineffective and said clutch means is effective into a second positionwherein said locking pawl is effective and said clutch means isineffective, 'abutment means including cooperating elements on saidneedle bar and said presser foot interengageable in the retractedposition of said needle bar for holding said presser foot in retractedposition, an upper thread control means for each needle bar responsiveto tension in the respective upper thread for controlling said drivingmeans, each said control means including an electric circuit, a normallyclosed switch in each circuit, and means operated by the associatedcontrol rod when the latter is moved into its said second position foropening said switch of said circuit to thereby make the circuitineffective.

References Cited UNITED STATES PATENTS 1,191,232 7/1916 Richards 112-2211,726,450 8/ 1929 Pettit 112-(239 2,768,593 10/1956 Lombard i12-2212,824,532 2/1958 Scheibel i12-221 3,259,088 7/1966 Rockholt 112-793,266,449 8/1966 Berg et al 112-221 3,282,237 11./1966 Niekrawietzi12-236 FOREIGN PATENTS 560,500 10/1932 Germany JORDAN, FRANKLIN,Primary Examiner.

H. HAMPTON HUNTER, Assistant Examiner.

